Dam and drive across Nant Meigan on Baron Hill estate

The dam and drive across Nant Meigan on the Baron Hill estate is a monumental masonry structure designed to close the head of Nant y Felin, impounding the stream for both industrial and picturesque purposes. It features coursed and random masonry that stands approximately 14 meters high, with a heavily battered profile supported by four large raked buttresses. At mid-height, there is a segmentally-arched and brick-vaulted tunnel that includes a projecting stone sill for the main water outlet, along with a ramped spillway situated between the buttresses. Lower down on the right, there is a second outfall beneath a long, now split, lintel that used to feed a stone-lined leat leading downhill to a former slate dressing mill, which was rebuilt in 1675. A driveway runs along the top of the dam, with a pond on the upper side, and continues north to a bridge over the B5109, leading to the ruins of Baron Hill beyond.